I currently have a 1982 300 SD Turbo Diesel, with over 300K on the odo. Sure it's not a convertible, and sure it's not gas, but it's a hell of a good car. Only problem I've had with it in the past 10 years was the A/C compressor and condensor which needed replacing.
And there's absolutely no rust on it at all. If you take good care of the chassis it'll last forever. And I don't know about the gas engines, but the diesels are bullet proof.
I'd say go for it. Not only are they solid cars, but they're easier to work on than the modern crap with all the wires and computers and shyte, where there's hardly enough room in the engine compartment to stick a screwdriver in.
And yup, the (O) light means brake pads need replacing, and the BRAKE light means the parking brake is set.
Another thing, see if you can find newer MB aluminium rims (the 15 inchers) to replace the stock 14 inch rims, it'll make a big difference in appearance. But that's a personal preference.
Take some pictures of your new car
